DNA tests are being carried out to determine whether the leader of al-Qaeda in Iraq, Abu Musab al-Zarqawi, was killed in a recent US-led raid.

Iraqi Foreign Minister Hoshyar Zebari says officials are testing DNA samples from several bodies found at the scene of the clashes in Mosul on Saturday.

US and Iraqi forces stormed what they believe was a safe house for senior al-Qaeda members.

The US envoy to Iraq has said he did not believe Zarqawi was among the dead.

Though US Army spokesman Barry Venable said US forces "employ whatever means required... to identify suspected or known terrorists or insurgents".

Eight suspected insurgents and four Iraqi police officers died in the raid.

On Tuesday, rebels fired a mortar round at a ceremony to mark the handing back by US forces of a presidential palace in Saddam Hussein's hometown to local Iraqi authorities.

The US ambassador to Iraq, Zalmay Khalilzad, was among those attending the ceremony. There were no reports of any casualties.

Doubts

"We know that American and Iraqi forces... surrounded a house where there was fierce resistance and when the American and Iraqi forces jointly tried to storm the building the occupants blew themselves up," Mr Zebari said.

"There must have been some key leaders from the terrorists, from the fundamentalists who committed suicide instead of handing themselves up," the minister added.

But Mr Khalilzad cast doubts on whether Zarqawi was killed.

"Unfortunately, we did not get him in Mosul," he said.

"Of course the days are numbered, we are after him, we are getting closer," the ambassador added.

Zarqawi - the Jordanian-born head of al-Qaeda in Iraq - is the American's most wanted person in Iraq.

His group has claimed responsibility for a number of deadly attacks in the country and also said it carried out triple hotel bombings in the neighbouring Jordan.